Chuck



Jnven/'an A J. MEHREN CHUCK Filed Dec. 4. 1930 fag. 3.

May 16, 1933.

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Patented May 16, 1933 marit es lea 'Le Joslin ivrnnnniv, F DUSSELDORF,GERMANY, assiernon 'ro Fin-M vnianmern srannwnnkn AKTIENGESELLSCHAFT, ornnssnnnonn, GERMANY CHUCK Application filed December 4, 1330, Serial No.500,057, and in Germany December 12, 1929.

The invention relates tov a chuck having joint simultaneous radialmovement of all the jaws. The invention-presents important advantages ine mparison with known devices of the kind.

lThere are numerous known types of chuck having joint radial movement ofthe jaws, most of which have for example vconical guides along which thejaws or lovers oit' the chuck move. In other constructions the radialmovement of the jaws is produced by the relative movement of two centralrinOs, on which the chuck memberis mounted. It has also been proposed toproduce a radial movement of the jaws to clamp the work by means ot atoothed segmentand rack secured to the jaw. Y

The defect of such apparatus is on the one hand that the radius ofaction of the chuck is extremely small, or cannot be varied eX- cept bytroublesome manipulations which entail loss or' time; that is to say themachine cannot be re-set for work of considerably larger or smallerdiameter except with considerable waste of time, if at all; Furthermore,the great disadvantage of known apparatus is the diiliculty of obtainingline.

l may be constructed with a small cone pinion adjustment of the jaws.

The present invention is fundamentally different in that the radius ofaction of the chuck can be modified within a wide range, and that theadjustment for taking work of a different diameter can be effected veryquickly, and with the greatest accuracy by means of line adjustment.

The apparatus according to the invention has the advantages hereinbeforementioned.

According to the invent-ion a worm and worm-wheel segment is employed'for producing the radial movement of the jaws, which are mounted on theworm. By these means the radius of action can be changed by the simpleturning of the worm, and the entire working programme of a machine canbe carried through with a single chuck, and without changing any of theparts, by merely selecting a worm of suitable length. The ine adjustmentof the jaws can be obtained by adjusting only a single worm, or aportion of the worms, instead of all of them simultaneously. rlhisensures that the work is perfectly centered at all times.

lt is known to accelerate the fixing 'of the work by using pneumaticcylinders, which either rotate the toothed segment through levers orelse, in the case of other typesof chuck, actuate conical bushes orguides. Such mechanism is also provided according to the presentinvention, the worin-wheel segment being set in motion by a lever and bythe advance of a piston pneumatically operated. Considering theelasticity ot the the chuck, in which case the possibility oi:V

secondary adjustment might be dispensed with. For such a case theinvention provides for a simultaneous joint adjustment of all the worms.For example, the apparatus mounted on the extension of each vworm shaft,allthese pinions being in engagement with a large conerring. f

i" great importance is attached both to very rapid and joint centraladjustment of all the worms, and to the possibility oa secondaryadjustment of the work, this problem is solved according to theinvention by providing a scr-ew between the worm and the jaw, thusenabling each jaw to be adj usted separately. It will be understood thatthis additional separate adjustment of each jaw can lbe effected bymeans of any other machine element, such as a pneumatically operatedpiston or the like.

The invention is illustrated by way of eX- ample in the accompanyingdrawing- Figure l is a section through a chuck as employed for a hollowspindle; Y

Figure' 2 showsV a chuck of the normal .L hype;

Figure 8 is a part sectional side elevation of an apparatus according tothe invention, and

Figure et is a part sectional side elevation showing a. modification.

The jaws 1 are coupled to worms 3, which are mounted in the chuck 2 andengage in a recess 4 in the jaw 1. The worms 3 also gear with worm-wheelsegments 5, which formy one end of two-armed levers 6, while the otherarms '-7 engage in recesses in a ring 8 (Figure 1) or a bush 9 (Figure2) disposed centrally lin relation to the axis of the spindle. By axialdisplacement of the ring 8 or the bush 9 which may be effected bypneumatic hydraulic or other means-fthey levers 6 are rotated on theirpivots, thus displacingA the worms 3 longitudinally without rotation.The jaws 1 are carried by the worms and by this means are allsimultaneously displaced radially. l

In this construction the radial adjustment of any one jaw is effected ina simple manner, in that the worm belonging to the jaw is rotated, forexample, by means of a tommy pin inserted in a corresponding gap in theworm. In this manner, as the worm-wheel segment remains in position, theworm is simultaneously advanced longitudinally, and thus moves the jawwith it.

Figure 3 shows the chuck with a joint ad-V justment for all the jaws bymeans of a cone ring 12 and cone pinion l1., rIhe cone pinion l1 carriesa driving shaft 10 with which the worm 3 is telescopically connected sothat on rotation of the cone pinion it rotates with the latter, and itis adapted to slide axially Y thereto. The telescopic connection iseffected in the present case by a sliding wedge or key, and it may alsobe effected by a squared driving shaft engageable in a similar shapedbore of the worm. The cone pinions belonging to all of the clamping jawsare interconnected by means of the intermediate ring 12. Thisintermediate ring transmit-s motion from the cone 1 1 to all of theother cone pinions or worm shafts, s`o that owing to the worm wheelsegments being at rest, all the 'worms are longitudinally displaced forthe same distance and correspondingly move the jaws. j

The swinging movement of the two armed lover 6 is introduced by theentraining of the lever end 7 during the longitudinal movement of thering 8, in Figure 1, or the head 9, in Figure 2.

Figure 4 shows a modification of the last- Y mentioned chuck in which,in addition to the joint adjustment of all the jaws, a separate fineadjustment is provided for each jaw by means of a screw-threadedspindle. A member 14, carrying the actual gripping face of the jaw, ismovably mounted on a member 13 of thejaw, which is coupled to anddisplaceable with the worm 3, and this member 14e can be independentlymoved by a Screw-` threaded spindle 15 rotatably mounted in the member13.

I claim:

1. A chuck comprising a head, jaws radially disposed in the head with atleast 011e of the jaws radially movable therein, a worm journaled in themovable jaw and held therein against axial movement, an angular leverpivoted to the head and having a segmental gear at the extremity of oneof its arms meshing with the worm, operating means engaging theextremity of the other arm of the lever to actuate said lever to movethe'worm axially to adjust the movable jaw radially in the head, thethread of the worm constituting a rack engaging the segmental gearduring said radial adjustment of the movable jaw, said operating meansalso acting to hold the angular lever stationary at the position towhich it is moved in the adjustment of the movable jaw and means forrotating the worm against the resistance of the segmental gear held bythe stationary angular lever to impart a supplemental radial adjustmentto the movable jaw.

2. A chuck as claimed in claim 1 wherein the means for rotating the wormcomprises a pinion fixed on 4a lshaft journaled in the chuck head andaxially splined in the worm, and an annular member rotatable in thechuck and having gear teeth meshingV with Vthepinion so that movement ofthe annular member rotates `the pinion to impart through the splinedshaft a rotary movement to the worm to effect a supplemental` radialadjustment to the movable jaw.

In testimony whereof I affix mv signature.

JOSEF MEI-IREN.

